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Sep 25, 2013, 04:18 PM

Step 15

Adding attach points to the cape.

Set the cape on the body as you did in step 14. On the cape, mark the locations of the mounting screws using the center of the body mounting blocks as a reference. Cut three 1.25 inch circles out of the 1/4" ply and glue them in place. Carefully cut two parallelograms and one triangle for the rear attach points. Use a slow dry epoxy to glue these blocks to the carbon tube, as shown.
Last edited by Otto Dieffenbach; Sep 26, 2013 at 01:26 PM.
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Sep 25, 2013, 04:20 PM

Step 16

Attaching the motor mount.

First attach the motor to the motor mount with appropriate hardware. Attach a 10 inch propeller to the motor so that you can check clearances during mounting. Make a triangular gusset for the lower side of the mount, as shown. Using the prop to center the motor, make alignment marks on the edge of the lateral motor support. Get a small piece of 6 mm Depron to use as a shim. Mixed some slow cure epoxy and have some CA with accelerator handy. Apply the epoxy to the mount and hold the motor in place, centered using your marks. Place the Depron shim under the prop tip, at the top plate. Now, dab a little CA at the ends of the motor mount/support joints and hit with accelerator. This will hold the motor in place as the slow dry epoxy hardens. Add the gusset to the bottom of the support and back of the mount.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 10:35 AM.
Sep 25, 2013, 04:21 PM

Step 17

Drilling holes for the 6 cape mounting screws.

You will need two drills bits; one will be small to get a good bite with the sheet metal screws and one will be just smaller than the diameter of the screw. Align the cape on the body and drill, with the small drill bit, the six mounting holes. Drill through the top of the cape and through the body mounting block.

Remove the cape and in the cape only, using the larger drill bit, re-drill the same 6 holes. The screws should easily screw into these holes and not fall out.

On the body, take a screw and Philips screw driver and carefully tread each hole. This should take some torque which means you will have a good bite and strong mount.
Last edited by Otto Dieffenbach; Sep 26, 2013 at 01:47 PM.
Sep 25, 2013, 04:23 PM

Step 18

Broom and body integration.

The broom handle is glued to the top of the leg plate. The wisp end (back of rudder) of the broom is 21 inches behind the tip of the feet. Check the broom alignment again and again.

Cut two 8..875 inch carbon fiber square tubes and fit them to the broom and the side ply stiffeners, as shown. It is important that these supports glue directly to the carbon square tube surface in the broom handle and solidly into notches in the side stiffeners. Use a slow curing epoxy to glue these in place.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 09:11 AM.
Sep 25, 2013, 04:25 PM

Step 19

Broom structure stabilization.

Cut one 7.625 inch carbon fiber square tube. It glues to the bottom surface of the broom handle and into slots cut into the leg plate. I used 5 min epoxy.

Cut two 9.25 inch Carbon Fiber strips and glue them flat to the edge of the vertical broom wisp on the top and bottom.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 09:15 AM.
Sep 25, 2013, 04:26 PM

Step 20

Broom handle stabilization.

Cut one14.5 inch carbon fiber square tube. Glue this square tube with slow dry epoxy to the motor mount support and gusset and to the carbon tube inside the broom handle.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 09:17 AM.
Sep 25, 2013, 04:28 PM

Step 21

Rudder control system installation.

I custom make my control horns due to the large surfaces. They are cut from 1/16 inch ply. The control horn is a triangle 1 x 2.5 inches. Drill the hole for the control rod connection and then rub thin CA around the hole area. After it cures, re-drill the hole.

Glue the control horn to the horizontal surface of the rudder. Mount/glue the rudder servo against the broom handle and carbon cross support. The picture shows an HS-81 servo but this gear train will not hold up. Use a metal gear servo like the HS-225MG from Hitec. Glue the control rod sheath to the side of the broom handle with 5 min epoxy. Be sure to rough the sheath surface lightly with 150 grit sandpaper to allow the glue to bite.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 09:26 AM.
Sep 25, 2013, 04:29 PM

Step 22

Main landing gear installation.

Use a steel axle and a carbon tube spacer between the wheels to mount to the side stiffeners. Use a 1/4 inch of plastic tube on the outside of the wheels as a spacer to the side stiffener. Glue the axle to the ply stiffener with slow dry epoxy.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 10:39 AM.
Sep 25, 2013, 04:31 PM

Step 23 (optional step)

Retracting front skid/wheel installation.

This is an optional step. The skid really helps in reducing the wear and tear on the structure. The skid length is 9.5 inches from the broom handle bottom to ground. I put a wheel on the end so I wouldn't poke my eye out. I use a $3 HXT-900 servo from HobbyKing and the Sea Fury retract gear from E-flite, around $10. The picture shows a carbon rod. This has been replace with a steel rod. You can opt for a non-retracting skid.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 10:40 AM.
Sep 25, 2013, 04:33 PM

Step 24 (optional step)

Creating a witches hat.

I mounted the witch's hat top using the same process as I used for the cape. The base is 1/16 inch ply, 1 inch wide. The hat top is a 12 x 6 inch triangle. The hat's brim is 13.75 inches from the front of the top plate and 12 inches wide. If you add the hat, the CG will be moved forward, as noted later.

See step 30 for hat modifications. These modifications add stability and make it easier to handle her prior to and after flight. By removing the hat top, the Witch can be set down on her back between flights.
Last edited by Otto Dieffenbach; Oct 06, 2015 at 09:38 AM.
Sep 25, 2013, 04:34 PM

Step 25

Elevator control system installation.

Basically the same approach as the rudder. The horns are the same size but can be made longer. I route a slot in the elevator and glue the horn into the slot with Gorilla Glue. If you Y connect the servos to the receiver remember to run the push rod to the top on one servo and the bottom on the other, as shown. Place these servos as far forward as the rods will let you and glue them into the cape fins.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 09:46 AM.
Sep 25, 2013, 04:36 PM

Step 26

Elevator structural strengthening.

I crack my elevators on a landing where a wind gust grabbed her. Cut two 7 inch carbon fiber strips and glue into a knife slit with CA, as shown.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 09:48 AM.
Sep 25, 2013, 04:38 PM

Step 27

Adding the arms.

The top of the arm is attached to the side 3/4 of an inch below the top plate. I sand a bevel on the inside with 150 grit to provide a good mating. Next, glue the lower arms on, as shown. They are reshaped and a little thinner for the witch.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 10:42 AM.
Sep 25, 2013, 04:39 PM

Step 28

Hiding the elevator servo wires.

Cut a hole in the Depron and run the servo wire through the hole. Route a channel to the center just behind the receiver location in the body. Lay the wires in the channels and tape over with packing tape.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 09:55 AM.
Sep 25, 2013, 04:41 PM

Step 29

ESC and receiver installation.

Find somebody with soldering skills. I located the ESC close to the battery, behind the hand. This requires a significant lengthening of the ESC motor wires. The receiver is located at the front of the top plate and against the head. You will need to lengthen the rudder servo wires and the ESC receiver wires. You will nee to cut a hole, in the top plate, behind the receiver to pass through the elevator servo wires. I secure the battery with rubber bands around the broom handle.
Last edited by Otto Dieffenbach; Sep 27, 2013 at 10:44 AM.

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